Rust

GMail SMTP Send using Previously Obtained OAuth2 Access Token

See more GMail SMTP/IMAP/POP Examples

Demonstrates how to send email using GMail and OAuth2 authentication. This example assumes an OAuth2 access token was previously obtained. Rust

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// See Get GMail SMTP Access Token 
// for sample code showing how to obtain a GMail SMTP access token for desktop apps.

// In this example, our access token was previously saved to the following file which contains JSON like this:
// 	{
// 	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
// 	 "token_type": "Bearer",
// 	 "expires_in": 3600,
// 	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
// 	}
// 
let json = chilkat::JsonObject::new();
if json.load_file("qa_data/tokens/_gmailSmtp.json").is_err() {
    println!("Failed to load GMail access token file.");
    return;
}

let access_token = json.string_of("access_token").unwrap_or_default();

let mailman = chilkat::MailMan::new();

// Set the properties for the GMail SMTP server:
mailman.set_smtp_host("smtp.gmail.com");
mailman.set_smtp_port(587);
mailman.set_start_tls(true);

// The SMTP username should be the GMail address of the user's account that authorized your app to send email.
mailman.set_smtp_username("chilkat.support@gmail.com");
mailman.set_o_auth2_access_token(&access_token);

// Create a new email object
let email = chilkat::Email::new();

email.set_subject("This is a test");
email.set_body("This is a test");
email.set_from("Chilkat <chilkat.support@gmail.com>");
let _ = email.add_to("Chilkat Admin", "admin@chilkatsoft.com");
// To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

// Call SendEmail to connect to the SMTP server and send.
// The connection (i.e. session) to the SMTP server remains
// open so that subsequent SendEmail calls may use the
// same connection.  
if mailman.send_email(&email).is_err() {
    println!("{}", mailman.last_error_text());
    return;
}

// You may close the connection here.  If the connection is kept open, 
// the next call to mailman.SendEmail will continue using the already-established connection
// (and automatically re-connect if needed).
if mailman.close_smtp_connection().is_err() {
    println!("Connection to SMTP server not closed cleanly.");
}

println!("Email Sent via GMail with OAuth2 authentication.");